/Engine/Plugins/Animation/MLDeformer/NeuralMorphModel/Source/NeuralMorphModelEditor/Public/NeuralMorphEditorModel.h
Get the mask visualization item index. This specifies which item (bone, curve, bone group, curve group) to visualize the mask for. The first index values are for all input bones. Indices that come after that are for curves, then for bone groups and finally followed by curve groups. So if there are 10 input bones and 4 bone groups, and the visualization index is 11, it means it's for the second bone group.
The item to visualize the mask for.
int32 GetMaskVisualizationItemIndex() const